Screaming and sobbing, a teenage girl dialed 911 to report that a friend had been yanked into her own home by a strange man who was stabbing and beating her.

By the time authorities arrived, the friend and three family members were dead.

Recordings of the unidentified teen's panicked calls were released Friday to The Associated Press as puzzled authorities near Conover, a town tucked amid rolling hills and farmland about 40 miles northwest of Charlotte, tried to piece together what happened.

They say Lisa Saephan and her three children — 20-year-old Melanie, 18-year-old Pauline and 3-year-old Cody — were stabbed or shot to death in their home early Thursday, apparently by a suspicious man seen outside that morning.

The friend who called 911 told authorities she saw a man outside the house when she drove up around 7 to give Pauline a ride to school. When they returned to the house to investigate, they heard crying through the front door, the friend told the 911 dispatcher.

"And then when she knocked on the door the guy opened it and he started beating her up ... he was stabbing her," the girl, who fled, told the dispatcher through sobs.

Brian Tzeo, Saephan's husband and the children's father, had left for work shortly before his family was killed. He is not a suspect and has been holed up in a hotel, where he is refusing to eat and saying he had no reason to live, said family friend Mai Cai, who lives next door.

"Right now, he's trying to cope," Cai said. "He hasn't eaten anything. I told him, 'you have to eat. You have to fight. Please keep fighting.' But he said to me, 'I don't need to be alive anymore. I don't need to live."'

Cai said he left for work at 6:15 a.m. Thursday and Brian Tzeo always left 15 minutes later for his job at a machine factory.

"Whoever did this knew the family's routine," Cai said. "They knew that Brian went to work the same time every morning."

Catawba County Sheriff David Huffman said that was probably correct.

"They did not arbitrarily pick that house," he said. "They knew who lived there and what the situation was because the father had gone to work in another county, apparently. The person apparently knew the pattern, if you will, that the three women and the little child would be there."

The sheriff's office held a debriefing Friday morning to divvy up assignments among the 30 investigators digging for clues in the case. Some spoke with witnesses and relatives. Others took to the streets, stopping drivers in the neighborhood and hoping for some clue about the mysterious man that will help narrow their focus.

Authorities were examining a gun found in a yard nearby. Huffman also said authorities found two stolen vehicles still running Thursday, one near the home and one near one of the victims' schools. He wasn't sure if the vehicles were connected to the killings.

"We're just grabbing at straws right now, but the information is coming in very good — both materially and verbally," Huffman said.

Friday night, authorities released a composite sketch of the strange man they believe was at the home. He had jet black hair and was last seen wearing a blue hooded sweat shirt and driving away in a black four-door sedan.

News of the deaths shocked many people in the subdivision, where word of the crime spread quickly, said Jim Williams, a truck driver who was walking near the home Friday.

"How could somebody do something like this?" he asked. "To kill a whole family. It's sick. We're all shaken up."